Field of the Invention
The present invention relates, in general, to a clutch torque control method for a dual clutch transmission (DCT) vehicle and, more particularly, to a technique for controlling clutch torque of a dry clutch constituting a DCT.
Description of Related Art
Dual clutch transmissions (DCTs) are designed to receive power from a power source such as an engine through two clutches, to selectively transmit the power to two input shafts that are set to allow a series of shift stages to realize respective odd and even number stages, and to cause the shift stages to be sequentially changed by torque handover by which one of the two clutches is engaged and the other is disengaged. Thereby, the shift stage can be changed to a higher or lower shift stage without reducing torque.
Among DCTs, some use the two clutches connected to the two input shafts as wet clutches, and some use the two clutches as dry clutches. Unlike the wet clutch, the dry clutch is subjected to a continuous change in torque-stroke (TS) curve characteristics that refer to characteristics of transmission torque of the dry clutch relative to a stroke of an actuator driving the dry clutch. As such, when the TS curve characteristics should be learned as frequently as possible and be accurately secured, and when the actuator should be controlled according to the accurately secured TS curve characteristics, the dry clutch can realize a stable operation when the shift stage is changed.
However, since in reality it is impossible to learn the TS curve characteristics of the dry clutch each time, when the change of the shift stage is controlled using the latest TS curve characteristics in an abruptly changed state or in an incompletely learned state, it results in controlling the actuator based on incorrect information. As such, a shift shock or an engine flare phenomenon in which the number of rotations of the engine is suddenly raised may occur.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.